Anemometer

Abstract

An anemometer, in which a preferably cylindrical flow-capturing surface (1) is fastened to the control lever (10) of an electrical transducer (2) which is fixed to the top of a support (16) mounted in a box (15). The flow-capturing surface (1) is fastened to a cylindrical hollow body (18) arranged in an annular chamber (19) which surrounds the electrical transducer (2) and the support (16) thereof. The upper part of the cylindrical body (18) is passed through an opening (315) formed in the upper wall (115) of the box and sealingly closed by a resilient annular collar (14) fixed to the cylindrical hollow body (18) and to the upper wall (115) of the box (15). The flow-capturing surface (1) is protected by a covering disc (23) fastened to the upper wall (115) of the box (15) by spaced thin rods (24).

I claim: 
     
       1. An anemometer, comprising: a) a box with a bottom part, side walls, an upper wall and chambers therein,   b) a flow-capturing surface which is responsive to a pressure force as exerted by an air flow and is mounted on the top of the box externally thereto, so as to be yieldable in all directions,   c) an electrical transducer fixed inside the box and comprising a control lever which is operatively connected to the flow-capturing surface so that the pressure force, as exerted by the air flow on the flow-capturing surface, is converted into electrical signals corresponding to the direction and to the extent of said force,   d) the flow-capturing surface being carried by the control lever of the electrical transducer and being fixed to a cylindrical hollow body arranged in an annular chamber which surrounds the electrical transducer and is of such a size as to permit the cylindrical body to oscillate in all directions transversely to its axis,   e) the cylindrical body having an upper part extending through an opening which is formed in the upper wall of the box and is closed by a annular collar made of resilient material, said annular collar having an inner circumference and an outer circumference and being sealingly fastened by at said inner circumference to the cylindrical body and at said outer circumference to the upper wall of the box,   f) said cylindrical body having an open bottom end and the electrical transducer being fixed to the top of a support which is fastened to the bottom part of the box and extends into the interior of the cylindrical body through the open bottom end thereof.   
     
     
       2. An anemometer according to claim 1, wherein the support to which the electrical transducer is fixed comprises a cylindrical hollow member and an amplifier for amplifying the signals from the transducer is accommodated under the transducer in the said cylindrical hollow member. 
     
     
       3. An anemometer according to claim 1, wherein the flow-capturing surface is interposed between the upper wall of the box and a covering disc which is attached to the box so that air-flow passages are provided around the flow-capturing surface. 
     
     
       4. An anemometer according to claim 3, wherein the covering disc is carried by the box by means of spaced thin rods. 
     
     
       5. An anemometer according to claim 3, wherein the covering disc is carried by the box by means of a cylindrical wall provided with slits for the throughflow of air. 
     
     
       6. An anemometer according to claim 1, further comprising electrical heating means provided in an annular chamber of the box under said collar. 
     
     
       7. An anemometer according to claim 1, further comprising a feeding circuit accommodated in a chamber in the bottom part of the box. 
     
     
       8. An anemometer according to claim 1, further comprising barometric means accommodated in a peripheral annular chamber of the box, said peripheral chamber being provided with slots communicating with the exterior. 
     
     
       9. An anemometer according to claim 1, wherein the flow-capturing surface has a rotational symmetry, the control lever of the electrical transducer being yieldably mounted in all directions of the air flow by means of a spherical bearing provided at an intermediate region of the control lever, one end of the control lever carrying the flow-capturing surface, while the other end thereof has affixed thereto an actuating member of the electrical transducer, said actuating member extending perpendicularly to said control lever. 
     
     
       10. An anemometer according to claim 9, wherein the electrical transducer comprises at least four individual electrical transducer elements arranged altogether perpendicularly to the control lever and disposed in a crosswise arrangement so that pairs of opposite electrical transducer elements are in alignment and define one axis of a system of coordinates for the resolution of the vector of the pressure force exerted on the flow-capturing surface, said pairs generating, when stressed, a signal corresponding to the value of the associated resolution coordinate of the vector of said force. 
     
     
       11. An anemometer according to claim 10 wherein the actuating member for the individual electrical transducer elements comprises a pressure disc which is arranged substantially co-planar with the plane containing the electrical transducer elements and adhering thereagainst. 
     
     
       12. An anemometer according to claim 11, wherein, in a condition of the control lever in which the control lever is being perpendicular to the plane containing the electrical transducer elements and which is the rest condition of the electrical transducer, the pressure disc bears against all electrical transducer elements with the same amount of force so that when the control lever reaches a position of maximum stress against one of the transducer elements of each pair, the stress exerted against the associated electrical transducer element of that pair is a minimum value, said anemometer further comprising a means for determining the electrical signal which corresponds to the magnitude of a component of the force vector along one of the axes of the system of coordinates, by comparing the pairs of signals obtained from the two associated transducer elements. 
     
     
       13. An anemometer according to claim 10, wherein the electrical transducer elements comprise potentiometric transducers. 
     
     
       14. An anemometer according to claim 1, wherein the electrical transducer comprises a joystick device, and on the free end of the joystick is fixed the flow-capturing surface. 
     
     
       15. An anemometer according to claim 1 wherein said annular collar comprises a bellows member. 
     
     
       16. An anemometer according to claim 10 wherein said electrical transducer elements comprise transformer transducers. 
     
     
       17. An anemometer according to claim 10 wherein said electrical transducer elements comprise piezoelectric semiconductor transducers.